The present invention relates to a method and a test kit for diagnosing Crohn""s disease. In particular, the invention relates to a method for easily and rapidly diagnosing Crohn""s disease by an immunologic or enzymologic method used in the field of clinical examinations.
In inflammatory intestinal diseases, Crohn""s disease and ulcerative colitis are classified into a group of cryptogenic and idiopathic inflammatory intestinal diseases and they are designated as intractable diseases by the Ministry of Health and Welfare. These diseases are diagnosed based on the diagnostic standards prepared by the group of researchers who conducted the investigation and research on intractable inflammatory intestinal diseases specified by the Ministry of Health and Welfare. More specifically, after excluding infectious enteritis by the stool culture or the like, the disease is diagnosed by a combination of the clinical findings and the results of gastrointestinal contrast-radiography, endoscopy and histological examinations. However, in some cases, the diagnosis is still difficult to make even by these methods. Particularly, it is difficult to distinguish Crohn""s disease from ulcerative colitis in many cases. In addition, skillful doctors are needed to conduct the gastrointestinal contrast-radiography and endoscopy examinations and these examinations usually cause the patients physical and mental pains. Under these circumstances, there is a worldwide demand for the development of a specific, accurate clinical examination method capable of easily and rapidly diagnosing Crohn""s disease and ulcerative colitis.
It was reported that blood serums of patients with Crohn""s disease contain antineutrophilic leukocyte antibodies (Targan, S., et al.: Gastroenterology, 96, A 505, 1989) and anti-small intestine antibodies (Bagchi, S., et al.: Clin. Exp. Immunol., 55, 44-48, 1984), while those of patients with ulcerative colitis contain antitropomyosin antibodies (Das, K. n., et al.: J. Immunol., 150, 2487-2493, 1993), anticasein antibodies (Knoflach, P., et al.: Gastroenterology, 92, 479-485, 1987) or antimucin antibodies. Although some of those antibodies were reported to be specific to the above respective diseases, no antibody examination has yet been employed in the diagnosis of these diseases for the following reasons: Although the antibodies were reported to be specific to Crohn""s disease or ulcerative colitis, the data on these diseases was insufficient so that accurate clinical examinations could not be conducted. For example, the number of the cases was too small (small intestine protein, tropomyosin and mucin) or they had no specificity (neotrophilic leukocyte and casein). From this viewpoint, it can be said that the development of an accurate clinical examination method capable of easily and rapidly diagnosing Crohn""s disease and ulcerative colitis by examining the specific serum antibodies is very important in the clinical field.
The object of the present invention is to provide an accurate clinical examination method capable of easily and rapidly diagnosing Crohn""s disease and ulcerative colitis in mammals, particularly human beings, and a test kit used for the method.
The present invention relates to (1) a method for diagnosing Crohn""s disease, which comprises detecting the presence of an immunoglobulin or immunoglobulins, reactive with an amylase, in a specimen.
The present invention also relates to (2) a method for diagnosing Crohn""s disease, which comprises detecting the presence of immunoglobulins, reactive with an amylase, in a specimen by an immunologic or enzymologic method.
Further, the present invention relates to (3) a method for diagnosing Crohn""s disease, which comprises detecting the presence of immunoglobulins, reactive with an amylase, in a specimen by an immunologic method comprising reacting immunoglobulins, reactive with the amylase, in a specimen with the amylase immobilized on a support, reacting the product with a labeled product of a substance reactive with the immunoglobulins that are reactive with the amylase and determining an amount of the labeled reaction product.
The present invention relates to (4) a method for diagnosing Crohn""s disease, which comprises detecting the presence of immunoglobulins, reactive with an amylase, in a specimen by the enzymologic method comprising reacting immunoglobulins, reactive with the amylase, in a specimen with the amylase and then determining the amylase activity of the reaction product.
The present invention relates to (5) a method for diagnosing Crohn""s disease according to the above methods, wherein the amylase is porcine amylase or bovine amylase.
The present invention relates to (6) a test kit for diagnosing Crohn""s disease by detecting the presence of immunoglobulins, reactive with an amylase, in a specimen, the kit comprising the amylase and a reagent for determining the amylase activity or a reagent for determining the marker enzyme activity.
The present invention relates to (7) a test kit for diagnosing Crohn""s disease by detecting the presence of immunoglobulins, reactive with amylase, in a specimen, by the immunologic method, the kit comprising a support on which the amylase is immobilized; an enzyme-labeled substance selected from the group consisting of an enzyme-labeled anti-human IgG antibody, an enzyme-labeled anti-human IgA antibody, an enzyme-labeled protein A, an enzyme-labeled protein G and an enzyme-labeled Jacalin; and an enzyme activity-determining reagent.
The present invention relates to (8) a test kit for diagnosing Crohn""s disease according to the above test kit, wherein the amylase is porcine amylase or bovine amylase.